In the US approach companies must respond to the new societal norms of corporate responsibility and accountability to all stakeholders. There is no statutory requirement for CSR, but its voluntary nature is the very source of its dynamism and innovative characteristics. This will induce a spontaneous and self-sustaining pattern of diffusion of the best practices from large companies down to small ones, from rich to poor countries, leading to effective market economy, liberal democracy and active civil society. The majority of US companies do not give trade unions a central role in their CSR strategy.